Tyler Hook looks at a rifle while holding his daughter, Emma, at Highsmith Guns on Jan. 2 in Greenfield, Ind. Highsmith Guns is seeing a rush on semiautomatic rifles. The AR-15 and AK-47 are the most popular. Tom Russo, Daily Reporter, via AP

People enter the Nation's Gun Show at the Dulles Expo Center on Dec. 30, 2012, in Chantilly, Va. Guillaume Meyer, AFP/Getty Images

People look at rifles at the Nation's Gun Show at the Dulles Expo Center. Guillaume Meyer, AFP/Getty Images

A display of bumper stickers at a gun show at the Dulles Expo Center. Guillaume Meyer, AFP/Getty Images

A woman look at weapons on Dec. 30, 2012, at the Nation's Gun Show in Chantilly. Guillaume Meyer, AFP/Getty Images

Gun collector and target shooter Roy Shanks holds a Smith and Wesson variation of the AR-15 rifle he purchased at the RK Gun Show in the Smokies on Dec. 28, 2012, in Knoxville, Tenn. Shanks said he had not planned to buy it so soon but decided to do it now in case Congress passes a ban on assault weapons. Michael Patrick, Knoxville News Sentinel, via AP

A wall display of military-style rifles is almost empty on Dec. 27, 2012, at Rocky Mountain Discount Sports in Casper, Wyo. The store sold out of the firearms after the Sandy Hook Elementary School shootings in Newtown, Conn., sparked concern over the possibility of anti-gun legislation. Alan Rogers, Casper Star-Tribune, via AP

People look at rifles and pistols at a gun show on Dec. 22, 2012, at the Eastman Gun Show at Jim Miller Park in Marietta, Ga. Mike Stewart, AP

Lance McCoy, right, an employee at Kizer Guns and Ammo, shows a variety of weapons to a customer on Dec. 20, 2012, near Nacogdoches, Texas. Andrew D. Brosig, The Daily Sentinel, via AP